A method of manufacturing the items in the active zone of the nuclear reactor (options)

 

(57) Abstract:

Usage: the invention relates to nuclear technology, in particular, to a technology of manufacturing the various elements of the active zone by the method of joint deformation new powder systems-fuel, regulators, etc. of the invention: method of manufacturing the items in the active zone includes filling in the original preparation of powder filling with the required neutron-physical characteristics, sealing the workpiece and getting ready element by deformation of the workpiece. The dimensions of the original parts - the shell thickness, the length and diameter of the original piece is chosen in accordance with certain mathematical expressions. After or in the process of deformation of the workpiece it rolled into a cylindrical spiral. 2 S. p. 3 C.p. f-crystals.

The invention relates to nuclear engineering, in particular to the technology of manufacture of the various elements of the active zone by the method of joint deformation new powder systems (APS) - fuel elements, regulators, burnable absorbers, reproducing materials absorbing elements, etc.

One of the directions in enhancing the manufacturability ishes, is joint processing, which provides the required density of the filler and the required size of the shell.

A known method of manufacturing the items in the active zone, in particular of a fuel rod, the method of joint extrusion [1], in which multiple operations seal core, giving it and the shell of the given shape. Preparation of core fuel rod is placed in the socket of the shell material, choke her tube and the thus prepared Assembly in a hot condition push on the press through the matrix. Depending on the modes of deformation during extrusion of various defects, such as breaks the shell and core, education undulating profile of the core, flows on the shell, etc. To increase the yield of products increase the thickness of the billet shell, part of which is removed after the deformation of the workpiece, for example by chemical etching. The ratio of the size of the workpiece is selected empirically, by trial.

The closest in technical essence to the described invention is a method for manufacturing the items in the active zone of the nuclear rector, including filling in the initial preparation on aluchemie defined parameters of the finished element by deformation of the workpiece [2] .

Plastic compression of the workpiece with powder filler in this process is produced by the simultaneous application of pulsating efforts, as a result of which the product is pressed from all sides and decreasing in cross-section, extends. In the compression not only changes the shape of the piece, but change the structure of the material properties of the shell and structure of the filler. The metal of the workpiece under the action of external forces is crimped and flows in both cavities of the stream. This causes a different direction of the friction forces acting on the workpiece in the zone of compression, resulting in defective areas and requires increasing the thickness of the workpiece with the subsequent removal of material to obtain the specified dimensions. The choice of modes of deformation of the workpiece is carried out from the perspective of reducing defects and virtually ignores the required degree of compaction of the filler. In addition, known methods allow to produce elements having a rod shape, as used methods of deformation, mainly, do not imply the finished items in the form of a cylindrical spiral.

The task of the described invention is the creation of methods for the production of active elements C is echnological of the deformation process.

The solution to this problem is provided by the implementation of a new technical result, which consists in reducing defects during deformation of the workpiece, which leads to the reduction of material losses of the shell and core material.

This technical result is achieved in that in the method of manufacturing the items in the active zone of the nuclear reactor, including filling in the original preparation of powder filling with the required neutron-physical characteristics, sealing the workpiece and receiving the set of parameters of the finished element by deformation of the workpiece so that the thickness (to) shell length (lo) and the diameter (Do) of the original piece choose from the following ratios:

,

where

Sabout.E.- the cross-sectional area of the shell of the finished item;

SK. E.- the cross-sectional area of powder filler in the finished item;

Sabout.about.- the cross-sectional area of the shell in the workpiece;

le- the length of the finished item;

K - coefficient of deformation of the sealing filler

and after deformation of the workpiece it rolled into a cylindrical spiral, and the workpiece is deformed to values characteristic dimension (De
DeDwith/ (A + 1),

where

for profiles, the cross section of which has a cylindrical surface with a diameter inscribed in a spiral circle only one common point;

for other profiles;

Dwith- outer diameter of the spiral;

the angle of spiral turns;

p- relative uniform deformation during testing of the sheath material the tensile condition before wrapped.

This result is achieved by the fact that according to the second variant of the invention in the method of manufacturing the items in the active zone of the nuclear reactor, including filling in the original preparation of powder filling with the required neutron-physical characteristics, sealing the workpiece and receiving the set of parameters of the finished element by deformation of the workpiece, the thickness (to), length (lo) and the diameter (Dooriginal billet choose from the following ratios:

< / BR>
where

Sabout.E.- the cross-sectional area of the shell of the finished item;

SK. E.- the cross-sectional area of powder filler in the finished item;

Sabout.E.- the cross-sectional area of the shell in the workpiece;

le- the length of the finished item;
with
and the workpiece to deform the value of the characteristic dimension (De) cross-sectional experiencing maximum deformation by twisting in a spiral and is selected from the relation:

DeDwith/(A + 1),

where

for profiles, the cross section of which has a cylindrical surface with a diameter inscribed in a spiral circle only one common point;

for other profiles;

the angle of spiral turns;

p- relative uniform deformation during testing of the sheath material in tension in the cold-worked condition.

In addition, the filler used nuclear fuel or neutron absorber, or a neutron moderator, or mixtures thereof, and/or mixtures thereof with a neutron-transparent matrix.

It is also in the process of deformation to produce at least one intermediate annealing, and after deformation to make the target annealing of the finished product.

An excellent feature of the present invention is that the choice of dimensions of the original piece in accordance with the above expression allows you to get ready the item without further refining and processing useto the La element production burnable absorber, made in the form of a spiral made of round wire element, nalivaeva coil to a coil with an outer diameter (Dwith) 7.5 mm and a length of 500 mm with a given density filler to 2.55 g/cm3in the form of a mixture of boron carbide absorber in neutron-transparent matrix of aluminum oxide in the zirconium alloy cladding, uniform deformation (p) is defined from reference books or on the results of preliminary tests of the sheath material in tension, equal to the value of 0.25, at an angle () of the lifting of coils of the spiral 5,985odetermine the outer diameter (Dethe resulting element of De1,506 = 1,506 mm

Given this limitation and provide the required structural load density (e) filler to 2.55 g/cm3when the shell thickness 0.15 mm choose the diameter Dethe finished item, equal to 1.3 mm, and the coefficient (K) of deformation of the seal equal to 1.25. Coefficient (K) determined experimentally beforehand depending on the parameters of the used filler and method of deformation. The coefficient for various types of real fillers is in the range from 1 to 10.

The geometrical characteristics of the element, the coefficients are calculated using geometricheskim the parameters of the finished item, choose the ratio of the geometric parameters of the tabout/Daboutprocurement, equal 0,09868.

When selected diameter (Dabout) procurement of 7 mm thickness (tabout) shell will be the value 0,691 mm, and the area (Sabout.about.) cross-section of the workpiece 13,6958 mm2while length (lethe resulting element length (labout) procurement will be equal respectively 7532 mm 298 mm

Then pre-dried powders of boron carbide and aluminum oxide are mixed in a predetermined weight ratio, for example in a ball mill for 10 to 16 hours, given the chosen values of the coefficient of deformation of the seal define density (o) and mass (Mabout) hinge filler in the blank:

< / BR>
The original round billet with a diameter of Daboutand the thickness taboutpre-sealed at one end by melting, for example, argon-arc welding or electron beam welding in vacuum, or by rolling, filled with filler using voronkovidnaya vibration stand with a frequency of 50 Hz for 3 minutes Then the addition of filler doubletrees on the vibrator for 3 to 4 minutes to reach the height of the powder column is equal to labout. Then seal the second end of the workpiece by setting the limit element.

oC.

If necessary, the finished item rightout. The element is fixed on the mandrel in a lathe and twisted into a spiral "round" end outside diameter (Dc), is equal to 7.5 mm, thus obtaining the spiral element to the settings that provides the exception of additional treatments to remove excess material of the shell, in case of exceeding the thickness of the shell of the set value or rejection of the product upon receipt of the finished item when the shell thickness is less necessary, and also eliminates cutting or scrapping of the product upon receipt of the length of the zone of the filling of the finished item, other than the required.

Example 2. Same as example 1, but the spiral perform dvuhaktnoy with the elevation angle of spiral turns = 11,84.. While the wire element is made of two parts with a length leeach and equal 3827 mm workpiece Length laboutequal to 151 EACE and revive dvuhaktnoy spiral end outside diameter (Dwith), is equal to 7.5 mm, getting ready element.

Example 3. Same as example 1, except that the spiral perform a single with the elevation angle of spiral turns = 11,84, i.e. with a pitch that is different from the diameter (Dethe resulting element. Similarly determines the size of the stock (taking into account the pitch of the helix), which is subjected to deformation. Further annealed wire element with a diameter of 1.3 mm is fixed on the mandrel and wound spiral with angle turns = 11,84with the final desired diameter Dwith= 7.5 mm, receiving the helical element with the given parameters and a length of 500 mm, While getting ready element with a profile cross-section other than a circle, it follows as Deto choose a characteristic cross-sectional dimension of experiencing maximum deformation in the winding of the spiral. If the cross-sectional profile has only a single point with a cylindrical surface with a diameter of inscribed circle of a spiral, for example, when the profile of circular cross section, triangular cross-section, facing the top of the inside of the spiral and the other, the characteristic dimension Deis based on the elevation angle of the spiral turns. Other profiles, the cross section of which, the reverse is pirali, for example, band profiles, have a characteristic size that can be calculated in a known manner when procustom the calculation of the cross section having the maximum voltage.

Example 4. For manufacturing absorbing element made in the form of a spiral of wire element with rectangular cross-sections and an external diameter of the helix Dwith= 12,4 mm and a length of 1000 mm with a density filler to 1.9 g/cm3in the form of boron carbide in the shell of silver (zirconium, or niobium, or alloys thereof), uniform relative deformation which when combined operations deformation and twisting of the spiral is equal to 0.04 at an angle of ascent of turns = 9,385determine the characteristic size - thickness (Detape. Due to the fact that the cross section of the wire is rectangular, i.e., its internal profile, facing the inside of the spiral, has a cylindrical internal surface many common points, the parameter A = 1/p= 25. . Given this limitation and provide constructive boot with the above density filler selected by the thickness (tabout) shell 0.1 mm choose De= 0,4 (Deobtained by calculation is 0,477), and the coefficient K is a deformation of the sealing filler of 1.46. as the ratio of tabout/Dabout= 0,131. When selected diameter (Dabout) procurement, equal to 6 mm, a thickness (tabout) shell will be mm 0,787

The original tubular blank is pre-sealed at one end reflow and fill the shaker filler with hopper feeder with a frequency of 50 Hz for 9 min and dopolniaut for 5 to 6 minutes to reach the height of the powder column, is equal to laboutafter which seal the second end of the workpiece by melting in an electron-beam installation. Next, the workpiece is deformed by the drawing roller dies with box, of rectangular form on line or drum drawing mills with subsequent rolling in smooth rolls for rolling mills with pay deformation per pass in 5 - 10 %. On the last pass simultaneously with the deformation of the workpiece produce twisting it into a spiral by setting the cage of the machine winding device in the form of a rotating mandrel or winding rollers, thus obtaining a spiral with the specified parameters.

The method provides the possibility of receiving coils of any shape is cylindrical, spiral of Archimedes, a member of the helix, and so on, and also improves the qualitative features of ihod accepted items the parameters which match the specified increases with 65 - 70 % up to 90 %.

1. A method of manufacturing the items in the active zone of the nuclear reactor, including filling in the original preparation of powder filling with the required neutron-physical characteristics, sealing the workpiece and receiving the set of parameters of the finished element by deformation of the workpiece, characterized in that the thickness (to), length (l) and the diameter (D0) of the original piece is selected from a ratio

< / BR>
where S.E. - the cross-sectional area of the shell of the finished item;

S.E. - the cross-sectional area of powder filler in the finished item;

S.about. - the cross-sectional area of the shell in the workpiece;

le- the length of the finished item;

K - coefficient of deformation control filler

and after deformation of the workpiece it rolled into a cylindrical spiral, and the workpiece to deform the values of the characteristic size (D) cross-sectional experiencing maximum deformation by twisting in a spiral and is selected from the relation:

D DS / (A + 1),

where the profiles cross-section which has a cylindrical surface the diameter of the inscribed and;

the angle of spiral turns;

p- relative uniform deformation during testing of the sheath material in tension, in a state before winding.

2. A method of manufacturing the items in the active zone of the nuclear reactor, including filling in the original preparation of powder filling with the required neutron-physical characteristics, sealing the workpiece and receiving the set of parameters of the finished element by deformation of the workpiece, characterized in that the thickness (to), length (l) and diameter (D) of the original piece choose from the following ratios:

< / BR>
where S.E. - the cross-sectional area of the shell of the finished item;

S.E. - the cross-sectional area of powder filler in the finished item;

S.about. - the cross-sectional area of the casing in a workpiece,

l - length of the finished item;

K - coefficient of deformation of the sealing filler, and, simultaneously with the deformation of the workpiece produce twisting it into a cylindrical spiral with a diameter Dwithand the workpiece to deform the values of the characteristic size (D) cross-sectional experiencing maximum deformation by twisting in a spiral and is selected from the relation:

the diameter d is inscribed in a spiral circle only one common point;

for other profiles;

the angle of spiral turns;

p- relative uniform deformation during testing of the sheath material in tension in the cold-worked condition.

3. The method according to p. 1 or 2, characterized in that the deformation of the workpiece carry out at least one intermediate annealing.

4. The method according to p. 1 or 2 and/or 3, characterized in that the finished item is subjected to final annealing.

5. The method according to p. 1 or 2 and/or 3 and/or 4, characterized in that the filler used nuclear fuel, and/or the neutron moderator, and/or neutron absorber, and/or mixtures thereof with nitrosopropane matrix.

 

Same patents:

The invention relates to methods of processing materials intended for use in the core of nuclear reactors

The invention relates to nuclear engineering and can be used in the gear casings fuel elements (cartridges) of fuel tablets

FIELD: atomic power engineering.

SUBSTANCE: device has welding chambers having apertures for inputting covers for pressurization, which concurrently are output apertures of heat-conductive elements, welding chambers electrodes, power source, transporting module for transverse product feed, common control system with blocks for parallel and serial connection, device for forming a break in secondary contour. Welding chambers are placed in parallel to each other at distance from each other, determined from formula S=t(m k+1), where S - distance between chambers axes, t - step of transport module, k - number of chambers in device equal to number of steps of transporting module in each singular step thereof, m - any integer starting from one, and control systems connected through parallel connection block to working tools of device of same names, and through block for serial connection to welding force drive and to device for forming break in secondary contour of power source, as well as to power source connected in parallel to welding chambers electrodes.

EFFECT: higher efficiency.

4 cl, 1 dwg

FIELD: nuclear power engineering; manufacture of fuel elements and their claddings.

SUBSTANCE: each weld of cladding and its plug are tested in facility equipped with units for clamping and revolving the claddings, scanning with carriage using weld inspection piezoelectric transducer and piezoelectric transducer for measuring wall thickness in measurement region, immersion bath, ultrasonic pulse generator, ultrasonic pulse receiver, microprocessor, analog-to-digital converter switch, and random-access memory.

EFFECT: enhanced quality of fuel elements and their operating reliability in reactor core.

1 cl, 1 dwg

FIELD: power engineering, namely nuclear power reactors, particularly sealing of fuel elements by means of contact butt welding with use of plugs.

SUBSTANCE: apparatus includes sealed welding chamber with housing non-detachable at operation and having through duct for feeding parts to welding zone; mechanisms for sealing welding chamber; device for feeding parts to welding zone; additional clamp of tube; mechanisms for gripping and fixing welded parts; drive device for supplying welding pressure; autonomous drive units. Mechanisms for gripping and fixing welded parts are in the form of collet chucks with respective drives. Welding pressure supply drive device is connected with electrode holder of plug. Welding chamber is restricted by non-detachable housing and flange-current supply lead that is fluid -tightly connected with housing and fixed relative to housing at operation. One collet chuck has annular detachable current supply lead in the form of sectors and it rests by its end at side of large base of petal cone upon said flange-current supply lead. Collet chuck of tube grip and electrode-holder of plug have coaxial electrically insulated one relative to other tie rods arranged in through duct of chamber and joined with autonomous drive units.

EFFECT: enhanced stability of process, improved quality of welded joint due to lowered misalignment of tube and plug.

1 dwg

FIELD: nuclear power engineering; manufacture of fuel elements for fuel assemblies of nuclear power reactors.

SUBSTANCE: proposed process line has mechanism for press-fitting bottom plug in calibrated end of can provided with cutoff gear for piece-by-piece feeding of bottom plugs of different types that incorporates bottom plug passage duct accommodating C-shaped member with reciprocating horizontal-motion actuator whose top flap has slot engageable with upper cylindrical part of bottom plug; bottom flap is longer than top one and is provided with bottom plug passage hole shifted toward edge of bottom flap; flaps are spaced apart through distance slightly longer than maximal length of thick end of bottom plug; rod designed for press-fitting bottom plug in calibrated end of can has bed with seat to receive bottom plug, maximal-size portion of seat following shape of bottom plug.

EFFECT: enlarged functional capabilities of process line for manufacturing fuel-element cans of different sizes.

1 cl 7 dwg

FIELD: mechanical engineering.

SUBSTANCE: proposed method is intended for manufacturing fuel elements using resistance-butt welding primarily for their joining to zirconium alloy cans. Welding is effected at equipment electrical resistance not over 30-fold resistance of can section forming welded joint having or not point discontinuities in the form of separate spots or chain of such spots forming no continuous line and measuring maximum ten thicknesses of weld in cross-sectional area of welded joint under check disposed at distance equal to two or three thicknesses of can wall from butt-end of plug located inside fuel element, welded joint being checked by uniformity of external fin. Length of poor fin formation section does not exceed 10% of joint perimeter.

EFFECT: enhanced quality of welds and reliability of fuel element sealing.

2 cl

FIELD: nuclear power engineering; tubular dispersed-core three-layer fuel elements.

SUBSTANCE: proposed method includes production of powder mixture, powder mixing in plasticizer environment, cold molding in core billet with plasticizer, thermal sintering, hot molding-calibration of fuel core, core placing in can made in the form of sleeve with annular slot, calibration, hot molding through die, and drawing; inner surface of external can of sleeve is provided with longitudinal bulges and outer surface bears bulge location marks; fuel core is provided with longitudinal flats and placed in sleeve taking care to align bulges of the latter with core flats; in the course of drawing marks are aligned on arbor ribs.

EFFECT: enhanced stability of active layer and can thickness in shaping polyhedral fuel elements.

1 cl, 4 dwg

FIELD: nuclear power engineering.

SUBSTANCE: proposed fuel assembly primarily designed for use in nuclear power reactors VVER-1000 and VVER-440 has composite bottom spacer grid built of at least two parts identical with respect to disposition of holes and total thickness of component parts equal to height of circular collar on bottom plug of fuel element, and tubular channel hole diameter for bottom plugs equal to diameters of lower ends of bottom plugs; the latter are secured in holes of aligned parts of bottom spacer grid by shifting component parts of bottom spacer grid relative to each other, by locking bottom plugs on circular collar of bottom plugs between annular projections of upper and lower parts of bottom spacer grid, and by aligning flow holes of bottom spacer grid component parts. Component parts of bottom spacer grid are rigidly fixed upon their shifting to bottom nozzle of fuel assembly in case of nonseparable type of assembly and loosely attached upon their shifting to bottom nozzle in case of separable type of assembly.

EFFECT: enhanced reliability of fixing fuel element plugs in bottom grid holes of separable and nonseparable fuel assemblies, reduced labor consumption for manufacture and assembly.

1 cl, 3 dwg

FIELD: nuclear power engineering; manufacture of fuel elements for fuel assemblies of power reactors.

SUBSTANCE: proposed process line has mechanism for weighing can charged with fuel pellets installed past retainer press-fitting mechanism; can is coupled through computer with mentioned weighing mechanism for outputting data on pure mass of pellets in can; γ-quanta detecting units and pellet enrichment automatic control installations are mounted on charged can guiding facility in the form of rolling train between its rollers throughout length of charged pellet stack; detecting units are disposed around pellet stack charged in can with collimation channels shifted throughout length of charged pellet stack; detecting units are provided with photoelectronic multipliers, spectrometers, and data acquisition, processing and outputting computer. Each detecting unit is provided with through hole passing can-displacement tungsten tube; shifted collimation channels are provided in top and bottom parts of tungsten tube; photoelectronic multipliers are disposed on butt-ends of detecting unit.

EFFECT: enhanced quality of fuel element manufacture.

3 cl, 3 dwg

FIELD: nuclear power engineering, possibly automatic line for producing fuel elements of fuel assemblies of power nuclear reactors.

SUBSTANCE: aggregate is provided with detachable device for measuring electric resistance of fitting. Said device is arranged between collet chucks being in open position and it is made of two dielectric members spring-loaded one relative to other. End of one of said members has shape corresponding to contour of annular turning formed coaxially on end of collet chuck for plug. End of second member has shape corresponding to contour of annular turning formed coaxially on end of fitting in collet chuck for fuel element envelope. Said device has spring-loaded contacts for measuring electric resistance between fitting inside collet chuck and collet chuck itself. Caprolactam is used as dielectric material.

EFFECT: enhanced efficiency and quality of contact butt welding at sealing fuel element.

2 cl, 3 dwg

FIELD: nuclear power engineering.

SUBSTANCE: members used for fastening fuel element in hole of bottom end spacer grid are made in the form of shortened plug that has coaxial blind hole on its butt-end formed by annular walls expanded (burnished) in hole of larger diameter within bottom end spacer grid.

EFFECT: enhanced reliability of fuel assembly, reduced manufacturing cost and structural material input.

1 cl, 3 dwg

Up!